Ball burnishing application for finishing sculptured surfaces in multi-axis machines

In this paper the ball burnishing as a finishing process of sculptured surfaces is studied. This technique is a quick, easy and cheap process for a significant surface quality improvement of high-end parts. Aiming at the burnishing of sculptured surfaces, the influence of each burnishing parameter on flat surfaces was previously studied. Taking into account these results, burnishing of sculptured surfaces was performed by two different strategies: continuous burnishing (CB) using 5-axis interpolation and patch burnishing (PB) using 3 + 2-axis interpolation. The results obtained show the importance of choosing optimal burnishing parameters for a roughness and hardness improvement. Thus, CB achieves a great improvement in roughness, but the process feed is limited by the maximum speed of machine tool rotary axes. Otherwise, PB allows applying the machine maximum feed, reducing the time to finish the workpiece, but at the expense of a slight increase in roughness on the border line between patches.